This invention relates to an angular and positional Deviation Adjusting Mechanism of an industrial robot hand for performing various operations and, more particularly, to such a mechanism of a hand for inserting workpiece into a hole.
Recently, industrial robots have come to be used extensively in a variety of industrial fields along the development of information apparatus and in response to the demand for saving man-power. Industrial robots, particularly those which function to grip workpieces to set them in machine tools and remove them therefrom, or to transport them, are required to be able to handle the workpieces efficiently. In other words, it is required for the robot hand to have a high degree of freedom and be capable of providing the functions of a man's hand to a greater extent.
To analyze the operation of a robot of quietly placing an object having a flat bottom on a table at a predetermined position thereof, the arm of the robot is advanced until the bottom of the object comes in touch with the table, then the object is rotated about the contact point until its bottom is in close contact with the table, and then the object is moved along the table to the predetermined position. It is required of the apparatus for effecting such a motion to be highly sensitive to even a small external force for a rotation of the gripped object as well as to be sufficiently rigid for transmitting a large force so as to more the object along the table. The applicant has proposed earlier a linkage which can meet these contradicting requirements as disclosed in Japanese Patent Publication No. 56-45758.
This linkage has a pair of columns, first and second linking members and an operating arm. It can readily receive a rotational motion about a compliance center without causing any displacement of the center at all before or after an action is made, while it can provide high rigidity for a linear motion in the displacement of the center.
With the prior art robot hand having a linkage of the type described above, however, the operation of inserting a workpiece into a hole cannot always be performed efficiently because the workpiece readily rotates about the contact point when it is about to be inserted.